Red 4 Blue
by GeneralGunnut
Summary: Sarge builds a time machine in an attempt to eliminate the Blues. However, the two teams are sent way back in time, and now must fight together in order to survive the zombie apocalypse.
1. Prologue

**Red 4 Blue**

**(Left 4 Dead/ Red vs Blue Crossover)**

**Prologue**

**-Setting and Blurb-**

Sarge comes up with another ridiculous plan to eliminate the Blues, and that is by using a time machine to go back in time and make the members of Blue Team to never exist. However, he isn't sure how safe the machine is, so he tricks the Blues into using it. The Blues survive the time travel, but only to find themselves in Fairfield, PA, in a middle of a zombie apocalypse. Now, they must fight hordes of the undead as they try to figure how to get back to their own time. Will they get back to their own time? Will the Reds end up saving the Blues? Will they screw up history? Most likely yes on the last question, but stay tune to find out.

**-Prologue-**

In the secret holo-room under Red Base in Valhalla, Sarge is at awe at the latest invention he has created. Surely, he would be able to defeat those dreaded Blues. He called out his men with his gruff southern commanding voice, "Simmons, Grif, Donut, in here, now!"

The three Spartans unenthusiastically walked into the room, wondering what stupid plan their commander has come up with this time.

"So, what dumbass plan or invention have you come with this time, Sarge?" asked Orange soldier named Grif.

"I hope it's an ice cream machine; I always wanted an Ice Cream Party," guessed the fruity soldier in Pink named Donut.

"Yes, it's an ice cream machine, and we're going to have cake and ice cream because we won the war," sarcastically answered Sarge, "and we're going to get medals and Grif, you get to drive the float."

"Really," replied Grif.

"No!" barked Sarge.

"Aww, you just dashed my dreams away."

"Quiet you," requested Simmons, the Spartan in Maroon armor.

"Thank you, Simmons," thank the Red Staff Sergeant, "Now, as I was going to say. I have figured out a way to get rid of those Blues."

"What, we give them a copy of Donut singing 'Happy Birthday, Mr. President'," joked Grif.

"Grif, if you open your mouth one more time, I'm going to create another one with my shotgun," threatened Sarge.

Even though Grif knew Sarge would never go through with his threat, he decided to shut up just so he could hear the old man's plan.

"Donut and Gentlemen behold," announced the mad man as he unveiled a ring-like portal that looked like a Stargate, "the Fargate!"

"The Fargate?" questioned the three grunts in unison.

"Better known as a time machine, men," explained Sarge as he stood their amazed by his genius.

"Umm, sir, that kinda looks like a Stargate, like from that T.V. series," pointed out Simmons.

"What do you mean?" questioned Sarge.

"Well, a Stargate is supposed to travel people or things from one planet or another," explained Simmons.

"That's why it's called a Fargate," replied Sarge, "it's supposed to travel people back in time."

"I don't know, Sarge, wouldn't you call it a Timegate instead, since that name implies time travel itself," said Grif.

"Or how about the Fungate," added Donut.

"Or how about let's call it the 'you guys just shut the hell up gate'," said Sarge.

"But you still haven't explained why traveling back in time would defeat the Blues," replied Simmons.

"I've been trying to get to that, but you guys keep interrupting me," barked the Sergeant. His three comrades went silent to listen what Sarge has to say. "Ok, this is my plan. We go back in time before they were born, and we kill their parents. That way, they would never have existed and thus we won the war."

"Excellent plan there, Sarge," sarcastically replied Grif, "so, are we going to reprogram Lopez to become an assassin and send him back into time."

Lopez, the Spanish-speaking robot in Brown armor, was in the back of the room repairing the fifth Warthog that the team wrecked this week. He was tried with that those idiots destroying their equipment that he had to fix. Hell, they couldn't understand what he said and usually mistook what he said, which allowed him to speak openly. "_No es necesario ser reprogramed para matar a ustedes." (I don't need to be reprogrammed to kill you guys)_

"Actually, Lopez is a much more valuable asset to our team than you are Grif," shot back Sarge, "but before we can use the Fargate, we need to see how safe it is."

"How so, Sarge?" asked Simmons.

"Well, if my calculations are correct, there is a 75% chance that going through this portal will tear our molecules apart. Which is why I need some human guinea pigs," explained Sarge.

"How about using Grif, sir?" suggested Simmons which made Grif reply with an angry "Hey!"

"Actually, I'm afraid if Grif survives, he might find a way to fuck something up in the past," replied Sarge.

"Aww, if that's your way of saying 'I care about you', then I take that as a compliment," sarcastically replied Grif.

"You wish."

"So, who's the test subject," asked Simmons.

"The Blues of course," answered Sarge.

"So wait, let me get this straight," clarify Simmons, "you created a time machine so you can go back in time to destroy the Blues before they were born, but you have no idea if the machine is safe or not, so you are going to trick the Blues into getting into the machine to see if it's safe. I see no fault of logic in your plan, sir." The last sentence was sarcasm.

"But couldn't they take advantage and use the opportunity to eliminate us," cautioned Donut, "because I don't want to not exist."

"Quiet you crybaby," commanded Sarge, "I've set the coordinate's way back in time, so there is no way they could take us out. If they make it, they will die of old age, and won't be able to screw us. If the test fails, they'll die. It's a win-win situation. Now, I need help moving the Fargate in front of their base." Sarge looked around the room to see the team's robot fixing up a Warthog. "Lopez, stop doing nothing and get over here! I need help moving the Fargate!"

Lopez echoed, _"__¿Por qué no hacerlo usted mismo viejo tonto?"(Why don't you get it yourself you dumb old man)_

"Thank you, Lopez. I'm glad you volunteered to carry the Fargate all by yourself."

"_¿Por qué hablo aún yo? (Why do I even speak?)_


	2. It's a Trap

**Chapter One: It's a Trap**

On the other side of Valhalla, there stood the Blue base. Besides the Blue drapes on the side of it, it was identical to their opponent's base. Inside the base, were two Spartans; one in light blue armor, the other had cyan armor on. The one in cyan was sitting, impatiently bored, while the other soldier was gaining frustration from his colleague's nagging about his boredom.

"Gzzz, I'm bored," stated the bored soldier "is there anything we can do, Church?"

"I don't know," replied Church, who was polishing his sniper rifle, "but complaining about it wouldn't fucking fix it, Tucker."

"Well, I'm just bored, that's all," explained Tucker, "I mean all we do is sit here, watch the Reds, and wait. I mean, I want some action."

"Well, soon enough, their Sarge is going to launch some kinda attack on us, which usually results in some stalemate, then things will get boring again," said Church, "for all I care, I'm glad we can have some rest without their distraction."

The two were silent again. The silence lasted for a good five minutes until Tucker interrupted the peaceful noise of it. "I'm bored; I wonder what the Reds are up too."

"You know what, I fucking hate you," concluded Church.

"I fucking hate you too, bud," replied Tucker, "By the way, what's Caboose up too?"

"What am I, his fucking babysitter?" answered Church, "he's probably running around, trying to chase some butterfly or something. All I care, I rather have him away from me."

All of a sudden, a Spartan in blue armor, armed with an assault rifle, came rushing into the base. Church and Tucker grunted as they saw their moronic comrade coming into their room.

"What is Caboose?" growled Church, who didn't tolerate Caboose's actions, for they usually lead the team in getting in trouble, or getting Church killed.

"Well," huffed Caboose as he was catching his breath, "I was chasing this pretty yellow butterfly when all of a sudden, I found this portal-thingy."

"Portal-thingy?" questioned the two other blues.

"Yeah!" replied Caboose, "come on guys, follow me."

"Wait, Caboose," but before Church could stop him, Caboose wandered off. "Ah damn it."

So, Church and Tucker went to follow their retarded teammate, screaming on the top of their lungs for him to stop. But, the idiot didn't listen and continue to lead his team to his discovery. Eventually, they were in the middle of the map, when Caboose stopped in front of massive ring-shape portal. It emitted a green light in the center. The three looked at the strange device before Tucker asked, "So, what does this thing do?"

"What thing?" replied Caboose, who seemed to forget what he was searching for.

"The portal," answered the irritable Church, "the big thing that you wanted to show us."

"I have no idea what you're talking about," innocently replied Caboose.

"Most of the time, we have no idea what you are talking," added Tucker, who was also getting frustrated at his special friend.

Church merely shook his head in disappointed, while giving a loud sigh. Suddenly, the group was startled by a loud, booming, recognizable voice that appeared out of nowhere.

"Follow Blues!" busted the gruff voice, "I am the magical...umm…Fargate! I will grant you any wish, but you must enter my portal!"

Church and Tucker recognized the voice as Sarge, and knew he was trying to trick them into entering the mysterious portal. However, Caboose, being the idiot he is, believed the voice to be some kinda deity, and replied, "You mean, you can grant me any wish I want."

"Caboose, its Sarge," warned Church, "he's trying to get us into that portal, so he could get rid of us."

"Don't listen to him, Blue," insisted the voice, "he's a non-believer, and thus he speaks only of lies."

"What the hell are you talking about, Red," replied Tucker, "we could see you behind that boulder."

The Blue Team stared at the obviously hidden Sergeant, who was squatting behind the giant rock, on top of the hill. Of course, the stubborn Sarge refused to acknowledge his failed camouflage and merely lied, "No, you don't"

"Yes we do," repeated Church.

"Ok then, you found me," admitted Sarge, "but how am I ever going to retrieve my cake if it's in that portal."

"Cake!" screamed Caboose, who went running towards the energy doorway.

"No!" shouted the other Blues, "The cake is a lie!" But Caboose ignored them like usual and ran straight through the portal.

"Damn that idiot," stated Tucker.

"Well, at least he's gone," added Church, who was unsympathetic at the lost of their friend.

Tucker then read the top of the portal, only to gasp into shock at the present danger they might have landed themselves into.

"Umm…Church, have you read the top of that portal?" asked the nervous Tucker.

"Nope, and I don't give a fuck," replied Church.

"Dude, Caboose just entered a time machine," informed Tucker.

"So, what are you worried about? He's gone in a different time. He won't be bothering us anymore."

"But, he's back in time, like in the past. Do you know how much damage he can do?"

"Look Tucker," assuring Church, "I've been to the past many times, and whenever I tried to change something, somehow it didn't change, like a predestination paradox or some shit."

"But, it's Caboose we're talking about," added Tucker, "he always finds away to screw something up."

Church took awhile to soak up Tucker's argument before admitting, "Damnit, we need to get him out." Somehow, Church always finds himself in a situation where he has to save humanity or some shit like that. Whether it's to fix a time paradox, or prevent some alien prophecy from destroying the universe, or trying to destroy a crazy, invincible A.I, Church is a "destined" hero, whether he likes it or not. "Let's get him before he screws up something." So, the two Blues ran into the time machine, in hopes to rescue Caboose.

Sarge got out of his hiding spot and shouted, "I did it; I got rid of the Blues! Victory is ours!" The rest of his team came running up to him, as the red leader continued his bragging. "I can't believe how stupid those Blues are."

"Wow, I can't believe your plan actually worked," stated the surprised Simmons.

"Well, that's a first," added Grif.

"Does that mean we get ice cream?" asked Donut.

"Yes, fruitcake, we get our ice cream," replied Sarge, who was still proud at his accomplishment. He then turned to Lopez. "Lopez, go get the ice cream. We deserve it, for this is a proud day to be a Red."

Lopez answered back, "Nosotros no tenemos helado usted idiota." _(We don't have any ice cream, you idiot)_

However, Sarge didn't understand Lopez, and merely ordered him to get his men ice cream on the double. All Lopez could do was to sigh, get the warthog, and drive to nearest grocery store (wherever the hell that is).


	3. Left 4 Blue

**Chapter Two: Left 4 Blue**

It was darkness. Everything was black, there numbness all over, their heads were pounding. The two Spartans got up from the ground. Their time trip has left Tucker and Church in a state of daze. They realized that they were in the middle of an abandoned street in a city unknown to them. It was an eerie sight in deed for the soldiers from the future. The cars were scattered across the street with no drivers or passengers in them. The once bustling stores were now out of business. Nothing seemed to be alive.

"Ugh, my fucking head, it hurts," stated Church.

"Yeah, mine too, buddy," agreed Tucker as he looked around in his surroundings.

"So, any idea where fuck we are?" asked Church.

"We're in the past, dude," answered Tucker.

"I know that, fucktard. I was talking about where exactly we were."

"We're in an abandoned city."

Church merely palmed his facemask then shot back irritably, "I know that. You're worse than Caboose at times."

"Whatever, dude," replied Tucker, "although, it seems strange that there's nobody is here, like what time period is this?"

Church just sighed then shook his head. "How about we ask that guy?" suggested Church as he pointed to a lone, pale man that was staggering across the street.

"He looks drunk," observed Tucker as the man tried to keep his balance, "it's kinda funny to watch."

"Come on, Caboose is on the loose in the past, and we have no idea," added Church. The man started to puke what appeared to be blood. "Maybe, you should do it."

"No way, dude. He looks sick. I'm not getting vomit on me. Besides, it's your idea, so you should do it."

"Fine, how about we both go?"

Tucker hesitantly nodded and the two blues walked up to the stranger. The man didn't seem to notice the duo walking up to him.

"Hey, do you know where we are?" asked Church, which the sickly man seemed to ignore. "What's today? Are you even listening to me?"

"Maybe I should ask the questions," suggested Tucker, "hey, did you person in blue armor like ours, kinda an idiot."

The man finally made a noise, but it wasn't what the duo expected. They got in return a moan. Slowly, the sickly man raised its head, and looked at the time travelers with his yellow, glassy eyes. His mouth opened up with yellow, jagged teeth, and foam pouring out. The man then violently tackled Church to the ground, trying to claw and bite through the Spartan's armor, but he couldn't penetrate it.

"Tucker, get this guy off of me!" frantically order Church.

Tucker swiftly obeyed and shoved the rabid man off of Church. He then punches him in the gut, followed by another punch in the face, which resulted in crazy man falling back. "What the hell is wrong with that guy?" asked Tucker as he helped Church get off from the ground. But before he got an answer, the very same man attacked Tucker, but the Blue was able to push him away from him and on to the ground. Tucker then grabbed his Battle Rifle and stated, "I have no choice, dude, but I'm going to shoot you." The rabid man ignored the soldier's threat, gave a load snarl, and charged Tucker. What was heard next was the discharge of a three-round burst, the splatter of blood, and the thump of a body hitting the ground. Church and Tucker then gathered at the corpse.

"What the hell is that thing?" asked Tucker, who was freaked out at the events that just happened.

Church merely gave a shrug. Clearly, where were the hell the Reds have sent them, it was clearly going to be their demise. Just then, the duo heard the sounds of screaming and howling coming towards them.

"Shit, what the hell is that?" frantically questioned Tucker, who was getting scared shitless.

The screaming was getting louder, as the Blues saw the shadows of a rushing mob, presumptively the same dead-like creatures that they just encountered. Church pulled out his sniper rifle and zoomed into the crowd. They were indeed the same monsters. They were men and women, young and old, short and tall. Their clothes were as colorful as the pale gray skin that covered their bodies, for the only color they had on their clothes were the crimson red blood of their victims. As the horde came closer, the duo was indecisive in what to do.

"Ummm Church, what should we do? I mean we can fight them, right?" wondered the frighten Tucker.

Church gave it some thought then came up with the best plan he could come up with, "Fuck that, we're running." As soon as Church said that, the two went off sprinting as fast as they could, trying to outrun the horde.

* * *

Eventually, the two lost the mob of crazy people, as they were hiding in a dark, empty convenient store. Church and Tucker were breathing hard. They ran five blocks before they noticed the opened building. Apparently, the store was converted to some sorta of safe room, for the windows were barricaded and the glass doors were replaced with red, heavy, steel doors. Still, the duo understood they were safe for only short time, for it was a matter of time before those things would be back again and maybe with bigger numbers. The duo still assessed their situation, and realized that they were screwed.

"Well, at least we know where and when we are," stated Tucker as he read a newspaper, "It looks like the year is 2010 and we are in Fairfield, PA."

"So, what do you think those things are?" asked Church.

"Well, according to the paper, I think they have something to do with this Green Flu," replied Tucker who showed Church the main head line, _"Green Flu Strikes Northeast."_

"Green flu, what kinda ass would name a disease like that?" questioned Church.

"I know, this is a zombie virus," replied Tucker.

"What the hell are you talking about, how the hell are these zombies."

"Well, they kinda act like zombies."

"But zombies don't move that fast, I call zombie bullshit."

"Well, what do think they are?"

"I don't know vampires I guess."

"Vampires?! They defiantly don't look like vampires, Church. I mean, vampires are suppose to suck people's blood, and turn into bats, and sparkle in the sun."

"Seriously, you've been reading Twilight. I never knew you were this gay."

"I don't read Twilight…besides; it's a total chick magnet. Women love sensitive men."

"Yeah, the only women who read Twilight are 14 year old emotional emo girls. I never knew you were a pedophile."

"Hey, women are women. Bow-chicka-bow-wow!"

"You're sick."

"Well, you're…" but before Tucker could finish they heard the voice of a familiar comrade.

"Hey guys!" greeted Caboose. He was standing at the end of the room. In his arms, he cradled a young woman, though she had grayish skin, white hair, barely any clothes on, and growling intensely, trying to struggle out of Caboose's strong grip.

"Umm…Caboose, where did you find her?" curiously asked Tucker.

"Oh, well," explained Caboose, "after I went through that teleport-portal thingy, I was here in this city. I quite lost and scared. But then I heard this crying, and so I followed the crying. It led me into this room, and this is where I found this girl. I felt sad for her because she was sad. So, I decided to do what any good person would do and comfort her. But when I got near her, she would growl at me for no reason. So, I decided, maybe she wanted candy. So, I got some chocolate by that counter over there and believe or not, she stopped growling when I got her the candy. So, when she was eating the chocolate, I decided to get close to her. Then, she got up and gave big hug, and in return, I gave her a hug. And I thought, you know who I should show my new friend to, my friends Church and Tucker."

Church and Tucker merely looked at each other, looked at the zombified woman, then looked at each other again. Caboose has screwed them once again.

"Caboose, maybe you should let go of that woman and run the hell away," suggested Tucker.

"Why?" asked the moron.

"Because she's a vampire," replied Church.

"You mean zombie," corrected Tucker.

"A zompire?" said Caboose, "Well, that's not a nice thing to say to our new friend. All she wants is a hug."

"Caboose no!" shouted Church and Tucker in unison but Caboose let go of the undead woman, causing her to charge the other two blues with sprinting speeds; her long sharp claws aimed at them with her bright amber eyes glaring. The duo quickly burst through the safety door and was on the streets again.

Tucker and Church were running as fast as they could, but the witch seemed to be gaining. Just then, they heard sounds of crackling coughs as long, slimy tongue wrapped around Tucker's body, constricting hi s breathing. He lost his balance, fell onto the ground, and started to drag along the pavement. Trying to muster whatever air he had, he screamed, "Church help me!"

Church looked around and saw his friend being lynched by a lurking, tall man on top of a building. Church took out his sniper rifle and aimed his rifle at the tall creature. He fired one shot and he missed. "Damn it," he said to himself, as he noticed the witch heading towards Tucker. He fired again but still missed. Eventually, he wasted the whole four round clip and his friend was still snared up. Church was never a great shooter, which is somewhat ironic, since had the only sniper rifle. As he reloaded for a second attempt, Church heard a deafening scream. Next thing he knew, he was on the ground with a hooded creature clawing at him. He screamed for help, but there wasn't any. "I guess this is it," thought Church, "We've been left for dead." He soon saw the witch catch up and started to claw at Tucker, causing him to scream in agony. "Although luckily for me, I was already dead."

Suddenly, gunfire erupted and the hunter that pounced on Church was shot off of him. The smoker puffed up in the smoke and the witch was crowned. "Did Caboose save them?" thought Church, "No, that idiot could have not been the hero. But, then again, Caboose did have his surprises." However, when Church looked up, he didn't see his moronic comrade, but instead four other humans.


End file.
